It is important for handymen to be able to dress, more specifically, to be able to sharpen, in a simple and convenient way, the tools that have become dull due to long and constant use. The common difficulty arising in such instance is that the tool, in particular a saw blade and/or a drill, has to be kept firmly in position during the sharpening so as to maintain the pertinent surfaces of the tool to be dressed in a defined position, so as to be easily dressed by a sharpening tool without endangering the user.
From U.S. Pat. No. 3,427,903 (further referred to as '903) a device for dressing a sawing tool having a plurality of sawing teeth is known. The device is described as having a support surface possessing a dressing side, on which the sawing tool can be placed. The support surface comprises guiding elements that run orthogonally to the dressing side and in which adjustable positioning elements are arranged. These positioning elements are used to firmly clamp the sawing tool to the support surface, hence immobilizing it to the support surface such that the support surface, itself displaceable by means of a feeding mechanism, can be successively moved past a dressing element of a dressing tool arranged in front of the support surface. The positioning elements act upon the side of the sawing tool opposite the dressing tool.
The device described in '903 has the disadvantage that it is not particularly suited for handymen due to its relatively complicated design. Another, more serious disadvantage of the device is that only elongated sawing tools such as for example, the saw blade of a hand saw, in which the teeth of the saw are arranged straightly and linearly, can be dressed.
Another disadvantage of the device described in '903, is that it does not permit sharpening of circular tools such as, for example, circular saw blades or circular milling tools. Indeed, to achieve the dressing of the individual teeth of the sawing tool, the support surface with the sawing tool firmly clamped onto it in a fixed position, has to be moved past the dressing tool by means of the feeding mechanism moving the support surface. Such arrangement does not permit to dress circular tools.
Yet a further disadvantage of the device described in '903 is that due to the arrangement of the dressing tool relative to the support surface, it is only possible to work on saw teeth possessing a triangular tooth contour. It is therefore not possible to sharpen saw teeth having a different configuration such as, for example, saw teeth of a trapezoidal shape. For the same reason it is not possible either to work on the back of saw teeth or on insert teeth.
It is therefore the object of the present invention to further develop a device of the aforementioned type so that the device according to the invention has a simple design and is particularity suited for the dressing of circular tools.